linux-kernel - RE: [NEW DRIVER V3 8/8] DA9058 REGULATOR driver

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Date:	Mon, 17 Sep 2012 10:49:22 +0000
From:	"Opensource [Anthony Olech]" <anthony.olech.opensource@...semi.com>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	"Opensource [Anthony Olech]" <anthony.olech.opensource@...semi.com>
CC:	Liam Girdwood <lrg@...com>, Guenter Roeck <linux@...ck-us.net>,
	"Jean Delvare" <khali@...ux-fr.org>,
	Randy Dunlap <rdunlap@...otime.net>,
	LKML <linux-kernel@...r.kernel.org>,
	David Dajun Chen <david.chen@...semi.com>
Subject: RE: [NEW DRIVER V3 8/8] DA9058 REGULATOR driver

> -----Original Message-----
> From: Mark Brown [mailto:broonie@...nsource.wolfsonmicro.com]
> Sent: 17 September 2012 11:40
> To: Opensource [Anthony Olech]
> Cc: Liam Girdwood; Guenter Roeck; Jean Delvare; Randy Dunlap; LKML; David
> Dajun Chen
> Subject: Re: [NEW DRIVER V3 8/8] DA9058 REGULATOR driver
> On Mon, Sep 17, 2012 at 10:29:43AM +0000, Opensource [Anthony Olech]
> wrote:
> > > Why is this function writing to the hardware, especially writing the
> > > same value every time?
> > the ramp_register is DA9058_SUPPLY_REG and it is marked as volitile.
> > Writing to the ramp enable bit starts the voltage change. When the
> > PMIC has finished making the change it resets the bit. Thus to make
> > another voltage change the bit needs to be set again.
> This function is retrieving the amount of time it would take to set the voltage.
> Why would it be starting a voltage ramp?  The fact that it's not setting the new
> voltage in the hardware ought to be a warning sign here...

Thanks for the quick response Mark,

I thought that the set_voltage_sel = regulator_set_voltage_sel_regmap callback first
set the target voltage, and that the set_voltage_time_sel = da9058_buck_ramp_voltage
callback was called afterwards?

was I wrong?

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